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No Model.)

W. A. CHURCH.

BALANCE RAIL PIN POR PIANOS.

No.v 373,924.

y Patented Nov. 29, 1887.

N. Patins Phomwhomphgr. washingxm n. c.

-, UNITED STATES PATENT GEEICE.

WALTER A. CHURCH, CE BTNCHAMTCN, NEW YORK.

BALANCE-RAIL. PIN FCR' PIANCS.

SPECIFICATION forming partof Letters Patent. No. 373,924, dated November 29, 1887.

Application filed June 16, 1887. Serial No. 241,544. (No model.)

To aZZ whom t may concern.-

Be it known that I, WALTER A. CHURCH, a citizen of the United States, residing at Binghamton, in the County of Broome and State of New York,-have invented certain new and useful Improvements in Piano-Forte Pins, of

of simple construction capable of permitting each key in said instrument to be raised or lowered or inclined to the right or left independently of the adjacent keys, so that a whole row can be leveled promptly without requiring the removal of any key.

In the accompanying drawings, Figure l is a perspective view of the key. Fig. 2 is a vertical section of the same with one of the keys of a piano and a portion of the cross-rail thereof shown by dotted lines in cross-section. Fig. 3 is a transverse section and in magnied size of the wire preferably -used in making the bottoni piece of the pin.

Fig. 4 isa vertical section of the socket or handle for driving the bottom piece of the pin in the cross-rail of a musical instrument.

The pin is made in two pieces. The lower piece, A, consists of suitablysized wire cut in short lengths, (of about one inch and a half,) oneend of which is pointed at a2, to facilitate its insertion into the cross-rail (also called the balance-rai1) of the musical iustrument, and the opposite end of which is screw-threaded at ai* to be inserted and retained in the piece B. The pointed end is preferably wedge-shaped, as an additional security againstrits turning or becoming loose after being driven into the cross-rail E, and for said security thevwire used in its construction may have one or more longitudinal ribs, et, thereon, as shown in Fig. 3. The piece B consists of a tubular stem, made either of spun metal or of a rod bored a portion of its length and screw-tapped, as shown at b, to receive the screw-threaded portion aB of the wire A. The lower portion of the piece B has a collar, b2, to form a rest for the lower edge of the piano-key C, and the up per end has suitable means for engagement with a tool to rotate it. These means may be a slot to receive the end of a screw-driver or a polygonal socket, or a polygonal stem, as b3.

The parts A and B are preferably made of substantially non-corrosive metal-for example, the part A of bronze and the part B of brass.

To drive the part Ain the crossrail E of a piano, I prefer to use a socket-ed metal handle, D, the socket d of which is of suitable diameter to loosely receive the screw-threaded end of the part A and of suitable depth to receive the length of the threaded portion intended to project above the said cross-rail, so that the end d2 of the handle acts as a stop and gage in its use. Therefore, to properly drive, set, and adjust my improved pin in a cross-rail the screw-.threaded end of the part A is inserted in the handle D, and the pointed end held upon the predetermined spot of said cross-rail and the handle driven with a hammer or mallet until its end dz abuts against said rail. The handle is then removed from over the part A, and the part B screwed upon the part A until its collar b2 is within a very short distance of said rail, and the operation is repeated for each pin in the instrument. A piano-key is then made to straddle each piu, so that it -rests upon the collar b2, and if the slots in said keys have been properly bored the whole series of keys can be very promptly leveled; but if any of said slots are not vertical, or if any of the keys are warped, they can be properly leveled by slightly bending laterally the bronze wire A at the point where it issues from the cross-rail, and said bending will not interfere with the vertical adj ustability of the part B upon the part A of the pin.

Having now fully described my invention, I claiml. A piano-key pivot-pin consisting of two parts, A and B, longitudinally adjustable upon each other, the part A being adapted to be driven and retained immovable in a piano cross-rail,and the part B being provided with a ange at one end and a stem at the other, substantially as described.

2. A piano-key pivot-pin consisting of two parts longitudinally adjustable upon each vIn testimony whereof I affix my signature in other, one part being adapted to be retained presence of two Witnesses.

immovable in a piano cross-rail andthe other provided with a iange, in combination with a WALTER A' CHURCH rail and an organ or piano key resting upon TN'DQSSGS: said flange, substantially as and for the pur- S. PERRY SMITH, pose described. N. A. ORUMB. 

